Subaru Impreza: EJ20/EJ25 head gasket weep at 80-120k km

GH/GE Impreza models with EJ20 and EJ25 naturally aspirated engines share the same multi-layer steel head gasket vulnerability as the prior generation. External coolant and oil seep typically appears at the cylinder deck face between 80,000 and 120,000 km. The EJ20 2.0-litre version is statistically less prone than the larger-bore EJ25 but is not immune. Progressive coolant loss and localised overheating will damage the head deck surface if seeping is left unaddressed, adding resurfacing or head replacement cost to the repair. Both banks should be inspected simultaneously as concurrent failure is common.

• Coolant seep or staining visible at cylinder head gasket line on either bank
• Oil seeping from head-to-block joint, sometimes mixed with coolant residue
• Slow coolant level reduction with no ground puddle or visible external leak
• Faint sweet smell from engine bay after shutdown
• Oily sheen or discolouration in coolant reservoir

1. 1

   Inspect both cylinder head gasket seam lines for coolant deposits, rust streaks, or oil film with engine warm.

2. 2

   Check the coolant reservoir cap underside for oil contamination indicating internal mixing.

3. 3

   Review workshop records for any cooling system repairs or coolant consumption notes.

Parts involved: Head gasket.

$1,600 to $3,500 at New Zealand independent workshop rates. That is for this job on its own, not for the car.

An estimate, in NZD, for the repair as normally carried out. What a specific car costs depends on which part has failed and what it damaged on the way — treat this as the floor for a negotiation, not a quote.

• “Has the head gasket ever been replaced or specifically inspected?”
• “Has coolant or oil consumption been noted between scheduled services?”
• “Is there any history of overheating events or low-coolant warnings?”

The failure described above is documented in published sources — owner forums, technical service bulletins, recall notices and workshop write-ups — held in our fault database. The inspection instructions and the cost estimate are KickTyres’ own interpretation of them, and it is a starting point for an inspection rather than a manufacturer statement.